Differential Diagnosis

The patient presents with a negative antinuclear antibody (ANA), negative rheumatoid factor (RF), elevated uric acid, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) without signs of gout. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Chronic Kidney Disease (CKD): Elevated uric acid can be seen in CKD due to decreased renal excretion. Inflammation markers like ESR and CRP can be elevated in CKD due to chronic inflammation. The absence of ANA and RF makes autoimmune causes less likely, and the lack of gout symptoms despite elevated uric acid points towards a metabolic rather than a crystalline arthropathy cause.

• Other Likely Diagnoses

  • Infectious Diseases: Chronic infections such as endocarditis, osteomyelitis, or abscesses can cause elevated inflammatory markers without specific autoimmune findings.
  • Malignancy: Certain cancers can lead to elevated uric acid (e.g., tumor lysis syndrome) and inflammation.
  • Familial Mediterranean Fever: Although it typically presents with recurrent febrile episodes and serositis, it can have elevated inflammatory markers between episodes and does not always present with a clear family history.

• Do Not Miss Diagnoses

  • Multiple Myeloma: A plasma cell dyscrasia that can cause elevated ESR and CRP due to the production of abnormal proteins. It's crucial to rule out due to its severe prognosis if left untreated.
  • Vasculitis: Conditions like giant cell arteritis or polymyalgia rheumatica can present with elevated inflammatory markers and do not always have specific autoantibodies. They are critical to diagnose due to the risk of severe complications if not treated promptly.
  • Sarcoidosis: Can cause elevated inflammatory markers and does not always present with specific autoantibodies. It's a diagnosis that can be easily missed but is crucial due to its potential for serious organ involvement.

• Rare Diagnoses

  • Tumor Lysis Syndrome: Although more commonly seen in the context of malignancy treatment, spontaneous tumor lysis can occur and would explain the elevated uric acid and inflammatory markers.
  • Autoinflammatory Disorders: Besides Familial Mediterranean Fever, other autoinflammatory disorders like TNF receptor-associated periodic syndrome (TRAPS) or hyper-IgD syndrome can present with recurrent fevers and elevated inflammatory markers without a clear autoimmune or infectious cause.